It is often desirable to flush oil through piping and components and determine whether metallic or other solid particulates are present in the oil to judge cleanliness of a system. During a shutdown of a turbine, for example for repair or other treatment of its turbine, it is recommended that the oil be flushed through the turbine to oil handling components, such as piping, to verify that the oil system meets cleanliness requirements. A verification of the cleanliness of the oil system is typically carried out by circulating the oil through a strainer assembly for a specified period of time, removing the strainer, washing any solid particles collected by the strainer onto a piece of filter paper, and analyzing the solid particles under a microscope.
A problem which exists is that of adequately getting the strainers clean enough prior to installation in the oil line that is to be flushed. Such strainers have typically consisted of a basket-type device, which may be about 1.5 inches (3.8 cm) in diameter and about 3 inches (7.6 cm) long, and lined with 150 mesh wire cloth, that is epoxied into place.
A new type of strainer or filter that has been suggested for use is a sampling screen assembly that would be used once and then discarded. This screen assembly comprises a polyester mesh that is secured between two gaskets, which screen assembly would be bolted or clamped between a pair of conventional pipe flanges, like a conventional flange gasket. A benefit of such a screen assembly is that its use would do away with the need to clean, and verify the cleanliness, of the screen. Such an assembly, however, would require flange bolt and nut manipulation for installation and removal of the screen assembly, as well as physically moving the flanges to affect installation or removal of the screen assembly.